Pittosporum tenuifolium Tom Thumb: A Miniature Marvel

Tawhiwhi

If you’re after a neat, stylish, and reliable shrub that quietly adds colour and structure to your garden all year round, then Pittosporum tenuifolium ‘Tom Thumb’ might be the one. With its neat, rounded shape and eye-catching dark purple foliage, this compact evergreen is an absolute gem for small gardens, containers, or as a contrast plant in a mixed border. It’s a great little performer with very little fuss — just the sort of plant every gardener should have up their sleeve!

In this guide, we’ll examine in detail how to grow and care for this stunning variety, including tips for planting in borders and pots, how to keep it happy and healthy throughout the seasons, and why it’s earned a place in so many gardens (including mine!).

What Makes ‘Tom Thumb’ So Special?

Pittosporum tenuifolium ‘Tom Thumb’ is a cultivated variety of the New Zealand native Pittosporum tenuifolium. While the original species can grow quite large, ‘Tom Thumb’ stays beautifully compact, rarely exceeding 1 metre (about 3 feet) in height and spread, which makes it ideal for smaller gardens or tight spaces. It has an elegant, rounded shape that looks smart even without pruning, although you can give it a gentle trim to keep things tidy if needed.

Its real showstopper quality is the foliage. New growth starts a vibrant green, then matures to a rich, deep purple — almost black in some lights — giving you a gorgeous contrast with neighbouring plants. You might also notice small, bell-shaped purple flowers with a sweet, honey-like scent in late spring to early summer. They’re subtle but lovely if you spot them up close.

Where and How to Grow ‘Tom Thumb’

‘Tom Thumb’ is incredibly versatile. It grows best in full sun to partial shade and will reward you with its best colour when it gets plenty of light. Too much shade can make the foliage a bit greener than purple, so if that rich colour is what you’re after, try to plant it somewhere with good sunlight.

It’s also a good idea to check your soil pH before planting — it prefers a neutral to slightly acidic soil. If you’ve got particularly alkaline soil, you might consider adding ericaceous compost or growing it in a container instead.

When planting in the garden, make sure your soil is well-drained. Pittosporums do not like sitting in soggy conditions. If your soil tends to be heavy or clay-based, dig in plenty of well-rotted manure to improve the structure and drainage. Adding a handful of slow-release fertiliser at planting time will boost your new plant and help it settle in more quickly.

If you’re planting into a container, which ‘Tom Thumb’ is brilliant for, choose a pot with good drainage holes and use John Innes No. 3 compost. This is a loam-based mix that holds nutrients well and provides good support for long-term container plants. Again, mix in some slow-release fertiliser and make sure the pot doesn’t sit in a saucer of water, especially in winter.

Planting Tips and Techniques

To plant Pittosporum tenuifolium ‘Tom Thumb’, dig a hole roughly twice as wide and deep as the root ball. Gently loosen the roots before placing them in the hole at the same depth it grew in its pot. Backfill with soil (or compost if you’re in a container), firm in gently with your hands, and water well. Finish with a generous layer of mulch to keep moisture in and weeds down.

It’s worth checking the pH of your soil using a simple home testing kit, which is available from most garden centres. Adding composted bark, or ericaceous compost, to the planting area can help adjust things slightly if it’s too alkaline.

Ongoing Care and Maintenance

Once established, ‘Tom Thumb’ is delightfully low-maintenance. During its first year, water regularly to help it get settled, especially in dry spells. After that, it will cope well with short periods of drought, although like most plants, it will appreciate a good drink during hot, dry weather.

Each spring, you can apply a fresh layer of mulch around the base to feed the soil and conserve moisture. A top-up of slow-release fertiliser in early spring will keep it looking lush and vibrant through the growing season. Liquid feeds aren’t necessary unless the plant is in a pot and showing signs of needing a boost.

Pruning is minimal—snip off any dead or damaged branches as needed. A light trim after flowering (usually early summer) will do the trick if you want to neaten the shape a bit. Avoid cutting back into old wood, as pittosporums don’t always regenerate well from hard pruning.

How Big Will It Get?

‘Tom Thumb’ is well-behaved in terms of growth. It reaches about 1 metre (3 feet) in height and spreads over several years, growing quite slowly. This makes it perfect for front-of-border planting, lining paths, or punctuating a gravel garden. You could also use it as a feature plant in a pot by the front door, where its rich colour and neat shape can shine.

Because it’s slow-growing, you won’t have to constantly clip or manage it, which is a big bonus in a busy garden. And even though it’s small, it holds its own when placed alongside taller grasses or lighter-coloured shrubs that make its deep foliage pop.

Where to Buy and What to Look For

Pittosporum tenuifolium ‘Tom Thumb’ is usually available at most good garden centres and is also widely available online through reputable nurseries. Choose healthy plants with vibrant, well-coloured leaves and no signs of mildew or root-bound pots.

It’s available in a range of sizes — from little 9cm starter pots to larger, bushier plants in 3L or even 10L containers. If you’re filling out a border, smaller plants will catch up in time, but if you’re looking for immediate impact, go for the larger sizes if your budget allows.

What are the Benefits of Growing Pittosporum tenuifolium Tom Thumb?

This compact evergreen shrub offers several benefits. Its dark purple leaves provide year-round colour, while its occasional honey-scented flowers add a delightful fragrance to your garden. Its low maintenance and compact habit make it ideal for smaller spaces or as part of a mixed border. The distinctive rounded shape creates a visually appealing focal point. The Tom Thumb also holds the prestigious RHS Award of Garden Merit, indicating its quality and reliability.

There’s a lot to love about this little shrub. It brings a stylish, contemporary feel to the garden without being fussy. The foliage colour is rich and dramatic — great for adding contrast — yet it still has that soft, rounded form that works beautifully in more relaxed or cottage-style borders. I’ve used it in sunny and part-shaded spots, and it never disappoints me.

It’s also one of those “plant and forget” types, which I always appreciate! A little mulch, a bit of a tidy once a year, and it just keeps going, looking smart through the seasons. It works wonderfully in pots — I’ve got one by the back door that’s been in the same container for years, and it’s still going strong. You’ll see why it has an RHS Award of Garden Merit — it is a great all-rounder.

Key Points to Remember:

• Awarded the RHS Award of Garden Merit for outstanding performance
• Compact and low-maintenance – perfect for borders or containers
• Striking foliage – deep purple leaves provide year-round interest
• Best in full sun or partial shade, in well-drained soil
• Add well-rotted manure to garden soil when planting
• Use John Innes No. 3 for pots or containers
• Feed with a slow-release ericaceous fertiliser each spring
• Check soil pH before planting – it prefers neutral to slightly acidic conditions
• Avoid waterlogged soil, and protect from severe frosts in colder regions
• Minimal pruning – a light trim after flowering is all that’s needed

Check out the RHS article here.

Still deciding? Hakonechloa macra Mulled Wine offers another brilliant option.

For more information on Shrubs for your garden please click here.

Q: What is Pittosporum tenuifolium ‘Tom Thumb’?

A: Pittosporum tenuifolium ‘Tom Thumb’, also known as tawhiwhi, is a small, attractive evergreen shrub with glossy dark green leaves. It’s a popular and hardy choice for low hedges, borders, or adding charm to various garden styles.

Q: How do I care for my tawhiwhi in winter?

A: Protect your tawhiwhi from cold, drying winds in winter. Ensure it’s planted in well-drained soil to avoid waterlogging, which is crucial during colder months.

Q: Does Pittosporum tenuifolium ‘Tom Thumb’ produce any flowers?

A: Yes, it reliably produces small, fragrant, dark purple flowers with a honey scent, typically blooming in the warmer months.

Q: Where can I buy tawhiwhi?

A: You can purchase tawhiwhi at most garden centres or online plant retailers. Look for healthy plants with characteristic dark stems.

Q: What kind of soil does Pittosporum tenuifolium ‘Tom Thumb’ prefer?

A: This plant prefers well-drained soil. While tolerant of some drying winds, excess moisture is harmful. Good drainage is essential.

Q: How big does ‘Tom Thumb’ get?

A: Pittosporum tenuifolium ‘Tom Thumb’ is a compact shrub with a slow growth rate, typically reaching about 60-90 cm (2-3 feet) in height and spread within a few years, maintaining a dense form.

Q: Can I use tawhiwhi for a privacy hedge?

A: Yes, this variety is suitable for creating low privacy hedges. Its dense foliage offers a good visual screen while remaining relatively compact.

Q: When is the best time to plant Pittosporum tenuifolium ‘Tom Thumb’?

A: Spring or early autumn are the best times to plant tawhiwhi, allowing roots to establish well before extreme summer heat or winter cold.